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      6.34.&nbsp;Bc-1.06.95
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        Linux From Scratch - Version 8.0
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        第六章&nbsp;安装基本系统软件
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      <h1 class="sect1">
        <a id="ch-system-bc" name="ch-system-bc"></a>6.34. Bc-1.06.95
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      <div class="package" lang="en" xml:lang="en">
        <p>
          Bc 软件包，包含一个处理任意精度数值的语言。
        </p>
        <div class="segmentedlist">
          <div class="seglistitem">
            <div class="seg">
              <strong class="segtitle">预计构建时间：</strong>
              <span class="segbody">0.1 SBU</span>
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            <div class="seg">
              <strong class="segtitle">所需磁盘空间：</strong>
              <span class="segbody">3.6 MB</span>
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          6.34.1. 安装 Bc
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        <p>
          首先，修复代码中一些小的内存泄漏问题：
        </p>
        <pre class="userinput">
<kbd class="command">patch -Np1 -i ../bc-1.06.95-memory_leak-1.patch</kbd>
</pre>
        <p>
          准备编译 Bc：
        </p>
        <pre class="userinput">
<kbd class="command">./configure --prefix=/usr           \
            --with-readline         \
            --mandir=/usr/share/man \
            --infodir=/usr/share/info</kbd>
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            <strong>配置选项的含义：</strong>
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            <dt>
              <span class="term"><em class=
              "parameter"><code>--with-readline</code></em></span>
            </dt>
            <dd>
              <p>
                此选项让 Bc 使用系统中已安装的 <code class="filename">readline</code> 库，而不是使用它自带的版本。
              </p>
            </dd>
          </dl>
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        <p>
          编译软件包：
        </p>
        <pre class="userinput">
<kbd class="command">make</kbd>
</pre>
        <p>
          如要测试 bc，运行下面的命令。输出会有点多，因此你可能会希望把它重定向到一个文件。测试中，最后一位数字会发生小概率的舍入误差（12144 次中会有 10 次）。
        </p>
        <pre class="userinput">
<kbd class="command">echo "quit" | ./bc/bc -l Test/checklib.b</kbd>
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        <p>
          安装软件包：
        </p>
        <pre class="userinput">
<kbd class="command">make install</kbd>
</pre>
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          <a id="contents-bc" name="contents-bc"></a>6.34.2. Bc 包含内容
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              <strong class="segtitle">安装的程序：</strong>
              <span class="segbody">bc 和 dc</span>
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            简介
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              <col />
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                  <p>
                    <a id="bc" name="bc"></a><span class="term"><span class=
                    "command"><strong>bc</strong></span></span>
                  </p>
                </td>
                <td>
                  <p>
                    是一个命令行计算器
                  </p>
                </td>
              </tr>
              <tr>
                <td>
                  <p>
                    <a id="dc" name="dc"></a><span class="term"><span class=
                    "command"><strong>dc</strong></span></span>
                  </p>
                </td>
                <td>
                  <p>
                    是一个反向修饰（运算符写在参数的最后面，一般是数字的最后面）的命令行计算器
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              </tr>
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